[PATCH 4.4 16/91] drm: rcar-du: Perform initialization/cleanup at probe/remove time

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>

commit c1d4b38c93069dca6b419a3b88907e01e2c3abf7 upstream.

The drm driver .load() operation is prone to race conditions as it
initializes the driver after registering the device nodes. Its usage is
deprecated, inline it in the probe function and call drm_dev_alloc() and
drm_dev_register() explicitly.

For consistency inline the .unload() handler in the remove function as
well.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Thong Ho <thong.ho.px@xxxxxxxxxxxxxxx>
Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/rcar-du/rcar_du_drv.c     |  187 ++++++++++++++++--------------
 drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c |   11 -
 drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c |   11 -
 drivers/gpu/drm/rcar-du/rcar_du_vgacon.c  |   11 -
 4 files changed, 106 insertions(+), 114 deletions(-)

--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -144,82 +144,6 @@ MODULE_DEVICE_TABLE(of, rcar_du_of_table
  * DRM operations
  */
 
-static int rcar_du_unload(struct drm_device *dev)
-{
-	struct rcar_du_device *rcdu = dev->dev_private;
-
-	if (rcdu->fbdev)
-		drm_fbdev_cma_fini(rcdu->fbdev);
-
-	drm_kms_helper_poll_fini(dev);
-	drm_mode_config_cleanup(dev);
-	drm_vblank_cleanup(dev);
-
-	dev->irq_enabled = 0;
-	dev->dev_private = NULL;
-
-	return 0;
-}
-
-static int rcar_du_load(struct drm_device *dev, unsigned long flags)
-{
-	struct platform_device *pdev = dev->platformdev;
-	struct device_node *np = pdev->dev.of_node;
-	struct rcar_du_device *rcdu;
-	struct resource *mem;
-	int ret;
-
-	if (np == NULL) {
-		dev_err(dev->dev, "no platform data\n");
-		return -ENODEV;
-	}
-
-	rcdu = devm_kzalloc(&pdev->dev, sizeof(*rcdu), GFP_KERNEL);
-	if (rcdu == NULL) {
-		dev_err(dev->dev, "failed to allocate private data\n");
-		return -ENOMEM;
-	}
-
-	init_waitqueue_head(&rcdu->commit.wait);
-
-	rcdu->dev = &pdev->dev;
-	rcdu->info = of_match_device(rcar_du_of_table, rcdu->dev)->data;
-	rcdu->ddev = dev;
-	dev->dev_private = rcdu;
-
-	/* I/O resources */
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	rcdu->mmio = devm_ioremap_resource(&pdev->dev, mem);
-	if (IS_ERR(rcdu->mmio))
-		return PTR_ERR(rcdu->mmio);
-
-	/* Initialize vertical blanking interrupts handling. Start with vblank
-	 * disabled for all CRTCs.
-	 */
-	ret = drm_vblank_init(dev, (1 << rcdu->info->num_crtcs) - 1);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to initialize vblank\n");
-		goto done;
-	}
-
-	/* DRM/KMS objects */
-	ret = rcar_du_modeset_init(rcdu);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to initialize DRM/KMS (%d)\n", ret);
-		goto done;
-	}
-
-	dev->irq_enabled = 1;
-
-	platform_set_drvdata(pdev, rcdu);
-
-done:
-	if (ret)
-		rcar_du_unload(dev);
-
-	return ret;
-}
-
 static void rcar_du_lastclose(struct drm_device *dev)
 {
 	struct rcar_du_device *rcdu = dev->dev_private;
@@ -260,10 +184,7 @@ static const struct file_operations rcar
 static struct drm_driver rcar_du_driver = {
 	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME
 				| DRIVER_ATOMIC,
-	.load			= rcar_du_load,
-	.unload			= rcar_du_unload,
 	.lastclose		= rcar_du_lastclose,
-	.set_busid		= drm_platform_set_busid,
 	.get_vblank_counter	= drm_vblank_no_hw_counter,
 	.enable_vblank		= rcar_du_enable_vblank,
 	.disable_vblank		= rcar_du_disable_vblank,
@@ -323,18 +244,116 @@ static const struct dev_pm_ops rcar_du_p
  * Platform driver
  */
 
-static int rcar_du_probe(struct platform_device *pdev)
+static int rcar_du_remove(struct platform_device *pdev)
 {
-	return drm_platform_init(&rcar_du_driver, pdev);
+	struct rcar_du_device *rcdu = platform_get_drvdata(pdev);
+	struct drm_device *ddev = rcdu->ddev;
+
+	mutex_lock(&ddev->mode_config.mutex);
+	drm_connector_unplug_all(ddev);
+	mutex_unlock(&ddev->mode_config.mutex);
+
+	drm_dev_unregister(ddev);
+
+	if (rcdu->fbdev)
+		drm_fbdev_cma_fini(rcdu->fbdev);
+
+	drm_kms_helper_poll_fini(ddev);
+	drm_mode_config_cleanup(ddev);
+	drm_vblank_cleanup(ddev);
+
+	drm_dev_unref(ddev);
+
+	return 0;
 }
 
-static int rcar_du_remove(struct platform_device *pdev)
+static int rcar_du_probe(struct platform_device *pdev)
 {
-	struct rcar_du_device *rcdu = platform_get_drvdata(pdev);
+	struct device_node *np = pdev->dev.of_node;
+	struct rcar_du_device *rcdu;
+	struct drm_connector *connector;
+	struct drm_device *ddev;
+	struct resource *mem;
+	int ret;
+
+	if (np == NULL) {
+		dev_err(&pdev->dev, "no device tree node\n");
+		return -ENODEV;
+	}
+
+	/* Allocate and initialize the DRM and R-Car device structures. */
+	rcdu = devm_kzalloc(&pdev->dev, sizeof(*rcdu), GFP_KERNEL);
+	if (rcdu == NULL)
+		return -ENOMEM;
+
+	init_waitqueue_head(&rcdu->commit.wait);
+
+	rcdu->dev = &pdev->dev;
+	rcdu->info = of_match_device(rcar_du_of_table, rcdu->dev)->data;
+
+	ddev = drm_dev_alloc(&rcar_du_driver, &pdev->dev);
+	if (!ddev)
+		return -ENOMEM;
+
+	drm_dev_set_unique(ddev, dev_name(&pdev->dev));
+
+	rcdu->ddev = ddev;
+	ddev->dev_private = rcdu;
 
-	drm_put_dev(rcdu->ddev);
+	platform_set_drvdata(pdev, rcdu);
+
+	/* I/O resources */
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	rcdu->mmio = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(rcdu->mmio)) {
+		ret = PTR_ERR(rcdu->mmio);
+		goto error;
+	}
+
+	/* Initialize vertical blanking interrupts handling. Start with vblank
+	 * disabled for all CRTCs.
+	 */
+	ret = drm_vblank_init(ddev, (1 << rcdu->info->num_crtcs) - 1);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to initialize vblank\n");
+		goto error;
+	}
+
+	/* DRM/KMS objects */
+	ret = rcar_du_modeset_init(rcdu);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to initialize DRM/KMS (%d)\n", ret);
+		goto error;
+	}
+
+	ddev->irq_enabled = 1;
+
+	/* Register the DRM device with the core and the connectors with
+	 * sysfs.
+	 */
+	ret = drm_dev_register(ddev, 0);
+	if (ret)
+		goto error;
+
+	mutex_lock(&ddev->mode_config.mutex);
+	drm_for_each_connector(connector, ddev) {
+		ret = drm_connector_register(connector);
+		if (ret < 0)
+			break;
+	}
+	mutex_unlock(&ddev->mode_config.mutex);
+
+	if (ret < 0)
+		goto error;
+
+	DRM_INFO("Device %s probed\n", dev_name(&pdev->dev));
 
 	return 0;
+
+error:
+	rcar_du_remove(pdev);
+
+	return ret;
 }
 
 static struct platform_driver rcar_du_platform_driver = {
--- a/drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_hdmicon.c
@@ -55,12 +55,6 @@ static const struct drm_connector_helper
 	.best_encoder = rcar_du_connector_best_encoder,
 };
 
-static void rcar_du_hdmi_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_unregister(connector);
-	drm_connector_cleanup(connector);
-}
-
 static enum drm_connector_status
 rcar_du_hdmi_connector_detect(struct drm_connector *connector, bool force)
 {
@@ -79,7 +73,7 @@ static const struct drm_connector_funcs
 	.reset = drm_atomic_helper_connector_reset,
 	.detect = rcar_du_hdmi_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = rcar_du_hdmi_connector_destroy,
+	.destroy = drm_connector_cleanup,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };
@@ -108,9 +102,6 @@ int rcar_du_hdmi_connector_init(struct r
 		return ret;
 
 	drm_connector_helper_add(connector, &connector_helper_funcs);
-	ret = drm_connector_register(connector);
-	if (ret < 0)
-		return ret;
 
 	connector->dpms = DRM_MODE_DPMS_OFF;
 	drm_object_property_set_value(&connector->base,
--- a/drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_lvdscon.c
@@ -62,12 +62,6 @@ static const struct drm_connector_helper
 	.best_encoder = rcar_du_connector_best_encoder,
 };
 
-static void rcar_du_lvds_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_unregister(connector);
-	drm_connector_cleanup(connector);
-}
-
 static enum drm_connector_status
 rcar_du_lvds_connector_detect(struct drm_connector *connector, bool force)
 {
@@ -79,7 +73,7 @@ static const struct drm_connector_funcs
 	.reset = drm_atomic_helper_connector_reset,
 	.detect = rcar_du_lvds_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = rcar_du_lvds_connector_destroy,
+	.destroy = drm_connector_cleanup,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };
@@ -117,9 +111,6 @@ int rcar_du_lvds_connector_init(struct r
 		return ret;
 
 	drm_connector_helper_add(connector, &connector_helper_funcs);
-	ret = drm_connector_register(connector);
-	if (ret < 0)
-		return ret;
 
 	connector->dpms = DRM_MODE_DPMS_OFF;
 	drm_object_property_set_value(&connector->base,
--- a/drivers/gpu/drm/rcar-du/rcar_du_vgacon.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_vgacon.c
@@ -31,12 +31,6 @@ static const struct drm_connector_helper
 	.best_encoder = rcar_du_connector_best_encoder,
 };
 
-static void rcar_du_vga_connector_destroy(struct drm_connector *connector)
-{
-	drm_connector_unregister(connector);
-	drm_connector_cleanup(connector);
-}
-
 static enum drm_connector_status
 rcar_du_vga_connector_detect(struct drm_connector *connector, bool force)
 {
@@ -48,7 +42,7 @@ static const struct drm_connector_funcs
 	.reset = drm_atomic_helper_connector_reset,
 	.detect = rcar_du_vga_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = rcar_du_vga_connector_destroy,
+	.destroy = drm_connector_cleanup,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };
@@ -76,9 +70,6 @@ int rcar_du_vga_connector_init(struct rc
 		return ret;
 
 	drm_connector_helper_add(connector, &connector_helper_funcs);
-	ret = drm_connector_register(connector);
-	if (ret < 0)
-		return ret;
 
 	connector->dpms = DRM_MODE_DPMS_OFF;
 	drm_object_property_set_value(&connector->base,